ActionScript Programming/PartI/Chapter 2

Operators (1)

In this chapter you will learn all of the operators which are used in ActionScript.

Usual operators

Operator	Description
" "	Text. Example: "hello", "hi", "button"
()	performs a grouping operation on one or more parameters, or surrounds one or more parameters and passes them as parameters to a function outside the parentheses. Example: trace ("hello!!!");

Arithmetic operators

Operator	Description
-	used for negating or subtracting. Example: a = 5 – 2; b = a -1;
%	calculates the remainder of expression1 divided by expression2. Example trace (12% 5); returns 2
*	multiplies two numerical expressions. Example: a = 5 * 5; b = a * 2;
/	divides expression1 by expression2. Example: a = 20 / 4; b = a / 5;
+	adds numeric expressions or concatenates (combines) strings. Example: a = 5 + 5; b = "hel" + "lo";

Assignment operators

Operator	Description
-=	assigns expression1 the value of expression1 -expression2. a = 5; b = 2; a -= b instead of a = a - b;
%=	assigns expression1 the value of expression1% expression2. a = 12; b = 5; a%=b instead of a=a % b;
*=	assigns expression1 the value of expression1 expression2. a = 2; b = 4; a = b instead of a = a * b;
/=	assigns expression1 the value of expression1/expression2. a = 4; b = 2; a /= b instead of a = a / b;
+=	assigns expression1 the value of expression1 + expression2. a = 3; b = 2; a += b instead of a=a + b;
=	assigns the type of expression2 to expression1. b = "hello"; z = b; c = z + "!!!";

Other operators are discussed later after chapter Data types.

Comments

Comments are useful for keeping track of what you intended, and for passing information to other developers if you work in a collaborative environment or are providing samples. There are two types of using comments. The first one is a one line comment and the other one: multi-line comment. For implementing one line comment just put "//" followed by your comment at the end of the line, if the line is not empty, and at the beginning of the line if it is empty. Examples:

This example demonstrates the use of comment at the end of the line

 box._rotation = 45;  //This rotates "box" object by 45 degrees

This example demonstrates the use of comment in an empty line

//This is just a comment

This example demonstrates the use of comment in an empty line in work

//Rotating "box" object by 45 degrees
 box._rotation = 45;

Note that you cannot use any type of comment inside the script! For implementing a multi-line comment you must just put your comment between symbols "/*" and "*/" (Note that all rules applied for one line comment are also applied for multi-line comment). Examples:

 /* We are now going to
    rotate our box by 45
    degrees */
 box._rotation = 45;
 
 box._rotation = 45; /* Rotating our box by 45 degrees */
 
 /* Rotating our box by 45 degrees */
 box._rotation = 45;
 // Box has been rotated!

You cannot use comments like this:

 box._rotation = 4/*just comment*/5;

This is a syntax error.

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